![Myron Stowe](/assets/img/avatar_default.png)
Use PCI Express Capability access functions to simplify device Capabilities Register usages. Signed-off-by: Myron Stowe <myron.stowe@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
575 lines
15 KiB
C
575 lines
15 KiB
C
/*
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* File: portdrv_core.c
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* Purpose: PCI Express Port Bus Driver's Core Functions
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*
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* Copyright (C) 2004 Intel
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* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
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*/
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/pm.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/pcieport_if.h>
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#include <linux/aer.h>
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#include "../pci.h"
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#include "portdrv.h"
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bool pciehp_msi_disabled;
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static int __init pciehp_setup(char *str)
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{
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if (!strncmp(str, "nomsi", 5))
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pciehp_msi_disabled = true;
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return 1;
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}
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__setup("pcie_hp=", pciehp_setup);
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/**
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* release_pcie_device - free PCI Express port service device structure
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* @dev: Port service device to release
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*
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* Invoked automatically when device is being removed in response to
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* device_unregister(dev). Release all resources being claimed.
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*/
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static void release_pcie_device(struct device *dev)
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{
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kfree(to_pcie_device(dev));
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}
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/**
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* pcie_port_msix_add_entry - add entry to given array of MSI-X entries
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* @entries: Array of MSI-X entries
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* @new_entry: Index of the entry to add to the array
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* @nr_entries: Number of entries aleady in the array
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*
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* Return value: Position of the added entry in the array
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*/
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static int pcie_port_msix_add_entry(
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struct msix_entry *entries, int new_entry, int nr_entries)
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{
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int j;
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for (j = 0; j < nr_entries; j++)
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if (entries[j].entry == new_entry)
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return j;
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entries[j].entry = new_entry;
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return j;
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}
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/**
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* pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port
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* @dev: PCI Express port to handle
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* @vectors: Array of interrupt vectors to populate
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* @mask: Bitmask of port capabilities returned by get_port_device_capability()
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*
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* Return value: 0 on success, error code on failure
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*/
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static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask)
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{
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struct msix_entry *msix_entries;
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int idx[PCIE_PORT_DEVICE_MAXSERVICES];
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int nr_entries, status, pos, i, nvec;
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u16 reg16;
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u32 reg32;
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nr_entries = pci_msix_table_size(dev);
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if (!nr_entries)
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return -EINVAL;
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if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES)
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nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES;
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msix_entries = kzalloc(sizeof(*msix_entries) * nr_entries, GFP_KERNEL);
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if (!msix_entries)
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return -ENOMEM;
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/*
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* Allocate as many entries as the port wants, so that we can check
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* which of them will be useful. Moreover, if nr_entries is correctly
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* equal to the number of entries this port actually uses, we'll happily
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* go through without any tricks.
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*/
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for (i = 0; i < nr_entries; i++)
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msix_entries[i].entry = i;
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status = pci_enable_msix(dev, msix_entries, nr_entries);
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if (status)
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goto Exit;
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for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
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idx[i] = -1;
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status = -EIO;
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nvec = 0;
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if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
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int entry;
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/*
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* The code below follows the PCI Express Base Specification 2.0
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* stating in Section 6.1.6 that "PME and Hot-Plug Event
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* interrupts (when both are implemented) always share the same
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* MSI or MSI-X vector, as indicated by the Interrupt Message
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* Number field in the PCI Express Capabilities register", where
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* according to Section 7.8.2 of the specification "For MSI-X,
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* the value in this field indicates which MSI-X Table entry is
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* used to generate the interrupt message."
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*/
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pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
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entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
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if (entry >= nr_entries)
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goto Error;
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i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
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if (i == nvec)
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nvec++;
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idx[PCIE_PORT_SERVICE_PME_SHIFT] = i;
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idx[PCIE_PORT_SERVICE_HP_SHIFT] = i;
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}
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if (mask & PCIE_PORT_SERVICE_AER) {
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int entry;
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/*
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* The code below follows Section 7.10.10 of the PCI Express
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* Base Specification 2.0 stating that bits 31-27 of the Root
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* Error Status Register contain a value indicating which of the
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* MSI/MSI-X vectors assigned to the port is going to be used
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* for AER, where "For MSI-X, the value in this register
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* indicates which MSI-X Table entry is used to generate the
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* interrupt message."
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*/
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pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
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pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
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entry = reg32 >> 27;
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if (entry >= nr_entries)
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goto Error;
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i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
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if (i == nvec)
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nvec++;
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idx[PCIE_PORT_SERVICE_AER_SHIFT] = i;
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}
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/*
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* If nvec is equal to the allocated number of entries, we can just use
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* what we have. Otherwise, the port has some extra entries not for the
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* services we know and we need to work around that.
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*/
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if (nvec == nr_entries) {
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status = 0;
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} else {
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/* Drop the temporary MSI-X setup */
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pci_disable_msix(dev);
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/* Now allocate the MSI-X vectors for real */
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status = pci_enable_msix(dev, msix_entries, nvec);
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if (status)
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goto Exit;
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}
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for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
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vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1;
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Exit:
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kfree(msix_entries);
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return status;
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Error:
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pci_disable_msix(dev);
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goto Exit;
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}
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/**
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* init_service_irqs - initialize irqs for PCI Express port services
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* @dev: PCI Express port to handle
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* @irqs: Array of irqs to populate
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* @mask: Bitmask of port capabilities returned by get_port_device_capability()
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*
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* Return value: Interrupt mode associated with the port
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*/
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static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
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{
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int i, irq = -1;
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/*
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* If MSI cannot be used for PCIe PME or hotplug, we have to use
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* INTx or other interrupts, e.g. system shared interrupt.
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*/
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if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) ||
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((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) {
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if (dev->irq)
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irq = dev->irq;
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goto no_msi;
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}
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/* Try to use MSI-X if supported */
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if (!pcie_port_enable_msix(dev, irqs, mask))
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return 0;
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/*
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* We're not going to use MSI-X, so try MSI and fall back to INTx.
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* If neither MSI/MSI-X nor INTx available, try other interrupt. On
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* some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
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*/
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if (!pci_enable_msi(dev) || dev->irq)
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irq = dev->irq;
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no_msi:
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for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
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irqs[i] = irq;
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irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
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if (irq < 0)
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return -ENODEV;
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return 0;
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}
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static void cleanup_service_irqs(struct pci_dev *dev)
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{
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if (dev->msix_enabled)
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pci_disable_msix(dev);
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else if (dev->msi_enabled)
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pci_disable_msi(dev);
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}
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/**
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* get_port_device_capability - discover capabilities of a PCI Express port
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* @dev: PCI Express port to examine
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*
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* The capabilities are read from the port's PCI Express configuration registers
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* as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
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* 7.9 - 7.11.
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*
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* Return value: Bitmask of discovered port capabilities
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*/
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static int get_port_device_capability(struct pci_dev *dev)
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{
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int services = 0;
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u32 reg32;
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int cap_mask = 0;
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int err;
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if (pcie_ports_disabled)
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return 0;
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err = pcie_port_platform_notify(dev, &cap_mask);
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if (!pcie_ports_auto) {
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cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
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| PCIE_PORT_SERVICE_VC;
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if (pci_aer_available())
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cap_mask |= PCIE_PORT_SERVICE_AER;
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} else if (err) {
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return 0;
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}
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/* Hot-Plug Capable */
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if ((cap_mask & PCIE_PORT_SERVICE_HP) &&
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pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT) {
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pcie_capability_read_dword(dev, PCI_EXP_SLTCAP, ®32);
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if (reg32 & PCI_EXP_SLTCAP_HPC) {
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services |= PCIE_PORT_SERVICE_HP;
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/*
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* Disable hot-plug interrupts in case they have been
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* enabled by the BIOS and the hot-plug service driver
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* is not loaded.
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*/
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pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
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PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
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}
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}
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/* AER capable */
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if ((cap_mask & PCIE_PORT_SERVICE_AER)
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&& pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
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services |= PCIE_PORT_SERVICE_AER;
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/*
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* Disable AER on this port in case it's been enabled by the
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* BIOS (the AER service driver will enable it when necessary).
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*/
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pci_disable_pcie_error_reporting(dev);
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}
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/* VC support */
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if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
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services |= PCIE_PORT_SERVICE_VC;
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/* Root ports are capable of generating PME too */
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if ((cap_mask & PCIE_PORT_SERVICE_PME)
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&& pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
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services |= PCIE_PORT_SERVICE_PME;
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/*
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* Disable PME interrupt on this port in case it's been enabled
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* by the BIOS (the PME service driver will enable it when
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* necessary).
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*/
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pcie_pme_interrupt_enable(dev, false);
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}
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return services;
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}
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/**
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* pcie_device_init - allocate and initialize PCI Express port service device
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* @pdev: PCI Express port to associate the service device with
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* @service: Type of service to associate with the service device
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* @irq: Interrupt vector to associate with the service device
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*/
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static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
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{
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int retval;
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struct pcie_device *pcie;
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struct device *device;
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pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
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if (!pcie)
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return -ENOMEM;
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pcie->port = pdev;
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pcie->irq = irq;
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pcie->service = service;
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/* Initialize generic device interface */
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device = &pcie->device;
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device->bus = &pcie_port_bus_type;
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device->release = release_pcie_device; /* callback to free pcie dev */
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dev_set_name(device, "%s:pcie%02x",
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pci_name(pdev),
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get_descriptor_id(pci_pcie_type(pdev), service));
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device->parent = &pdev->dev;
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device_enable_async_suspend(device);
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retval = device_register(device);
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if (retval)
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kfree(pcie);
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else
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get_device(device);
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return retval;
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}
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/**
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* pcie_port_device_register - register PCI Express port
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* @dev: PCI Express port to register
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*
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* Allocate the port extension structure and register services associated with
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* the port.
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*/
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int pcie_port_device_register(struct pci_dev *dev)
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{
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int status, capabilities, i, nr_service;
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int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
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/* Enable PCI Express port device */
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status = pci_enable_device(dev);
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if (status)
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return status;
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/* Get and check PCI Express port services */
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capabilities = get_port_device_capability(dev);
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if (!capabilities)
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return 0;
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pci_set_master(dev);
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/*
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* Initialize service irqs. Don't use service devices that
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* require interrupts if there is no way to generate them.
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*/
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status = init_service_irqs(dev, irqs, capabilities);
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if (status) {
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capabilities &= PCIE_PORT_SERVICE_VC;
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if (!capabilities)
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goto error_disable;
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}
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/* Allocate child services if any */
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status = -ENODEV;
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nr_service = 0;
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for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
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int service = 1 << i;
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if (!(capabilities & service))
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continue;
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if (!pcie_device_init(dev, service, irqs[i]))
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nr_service++;
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}
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if (!nr_service)
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goto error_cleanup_irqs;
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return 0;
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error_cleanup_irqs:
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cleanup_service_irqs(dev);
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error_disable:
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pci_disable_device(dev);
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return status;
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}
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#ifdef CONFIG_PM
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static int suspend_iter(struct device *dev, void *data)
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{
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struct pcie_port_service_driver *service_driver;
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if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
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service_driver = to_service_driver(dev->driver);
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if (service_driver->suspend)
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service_driver->suspend(to_pcie_device(dev));
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}
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return 0;
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}
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/**
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* pcie_port_device_suspend - suspend port services associated with a PCIe port
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* @dev: PCI Express port to handle
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*/
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int pcie_port_device_suspend(struct device *dev)
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{
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return device_for_each_child(dev, NULL, suspend_iter);
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}
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static int resume_iter(struct device *dev, void *data)
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{
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struct pcie_port_service_driver *service_driver;
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if ((dev->bus == &pcie_port_bus_type) &&
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(dev->driver)) {
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service_driver = to_service_driver(dev->driver);
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if (service_driver->resume)
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service_driver->resume(to_pcie_device(dev));
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}
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return 0;
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}
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/**
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* pcie_port_device_suspend - resume port services associated with a PCIe port
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* @dev: PCI Express port to handle
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*/
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int pcie_port_device_resume(struct device *dev)
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{
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return device_for_each_child(dev, NULL, resume_iter);
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}
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#endif /* PM */
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static int remove_iter(struct device *dev, void *data)
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{
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if (dev->bus == &pcie_port_bus_type) {
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put_device(dev);
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device_unregister(dev);
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}
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return 0;
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}
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/**
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* pcie_port_device_remove - unregister PCI Express port service devices
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* @dev: PCI Express port the service devices to unregister are associated with
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*
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* Remove PCI Express port service devices associated with given port and
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* disable MSI-X or MSI for the port.
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*/
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void pcie_port_device_remove(struct pci_dev *dev)
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{
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device_for_each_child(&dev->dev, NULL, remove_iter);
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cleanup_service_irqs(dev);
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pci_disable_device(dev);
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}
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/**
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* pcie_port_probe_service - probe driver for given PCI Express port service
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* @dev: PCI Express port service device to probe against
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*
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* If PCI Express port service driver is registered with
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* pcie_port_service_register(), this function will be called by the driver core
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* whenever match is found between the driver and a port service device.
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*/
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static int pcie_port_probe_service(struct device *dev)
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{
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struct pcie_device *pciedev;
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struct pcie_port_service_driver *driver;
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int status;
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if (!dev || !dev->driver)
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return -ENODEV;
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driver = to_service_driver(dev->driver);
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if (!driver || !driver->probe)
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return -ENODEV;
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pciedev = to_pcie_device(dev);
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status = driver->probe(pciedev);
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if (!status) {
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dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
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driver->name);
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get_device(dev);
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}
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return status;
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}
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/**
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* pcie_port_remove_service - detach driver from given PCI Express port service
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* @dev: PCI Express port service device to handle
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*
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* If PCI Express port service driver is registered with
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* pcie_port_service_register(), this function will be called by the driver core
|
|
* when device_unregister() is called for the port service device associated
|
|
* with the driver.
|
|
*/
|
|
static int pcie_port_remove_service(struct device *dev)
|
|
{
|
|
struct pcie_device *pciedev;
|
|
struct pcie_port_service_driver *driver;
|
|
|
|
if (!dev || !dev->driver)
|
|
return 0;
|
|
|
|
pciedev = to_pcie_device(dev);
|
|
driver = to_service_driver(dev->driver);
|
|
if (driver && driver->remove) {
|
|
dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
|
|
driver->name);
|
|
driver->remove(pciedev);
|
|
put_device(dev);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* pcie_port_shutdown_service - shut down given PCI Express port service
|
|
* @dev: PCI Express port service device to handle
|
|
*
|
|
* If PCI Express port service driver is registered with
|
|
* pcie_port_service_register(), this function will be called by the driver core
|
|
* when device_shutdown() is called for the port service device associated
|
|
* with the driver.
|
|
*/
|
|
static void pcie_port_shutdown_service(struct device *dev) {}
|
|
|
|
/**
|
|
* pcie_port_service_register - register PCI Express port service driver
|
|
* @new: PCI Express port service driver to register
|
|
*/
|
|
int pcie_port_service_register(struct pcie_port_service_driver *new)
|
|
{
|
|
if (pcie_ports_disabled)
|
|
return -ENODEV;
|
|
|
|
new->driver.name = (char *)new->name;
|
|
new->driver.bus = &pcie_port_bus_type;
|
|
new->driver.probe = pcie_port_probe_service;
|
|
new->driver.remove = pcie_port_remove_service;
|
|
new->driver.shutdown = pcie_port_shutdown_service;
|
|
|
|
return driver_register(&new->driver);
|
|
}
|
|
EXPORT_SYMBOL(pcie_port_service_register);
|
|
|
|
/**
|
|
* pcie_port_service_unregister - unregister PCI Express port service driver
|
|
* @drv: PCI Express port service driver to unregister
|
|
*/
|
|
void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
|
|
{
|
|
driver_unregister(&drv->driver);
|
|
}
|
|
EXPORT_SYMBOL(pcie_port_service_unregister);
|